Vacuum Arc Remelting Process
During VAR vacuum furnace, an electric arc is struck at the tip of an air melted ingot (known as an electrode), melting the material within the vacuum container. As the melting electrode drips into the bottom of the vessel, the surface area of each falling drip is exposed to the environment of the vacuum, which removes any residual gases from the alloy. The chemical and physical uniformity of the material is significantly improved when melting in this way. Dissolved gases such as hydrogen, nitrogen and oxygen are removed and the frequency of non-metallic inclusions is reduced. The resulting remelted material has much improved mechanical properties, including greater tensile ductility as well as superior impact and fatigue resistance, particularly in the transverse direction.